A simple star display and interactive star rating widget

star_rating.dart

import 'package:flutter/material.dart';

class StarDisplayWidget extends StatelessWidget {
  final int value;
  final Widget filledStar;
  final Widget unfilledStar;

  const StarDisplayWidget({
    Key key,
    this.value = 0,
    @required this.filledStar,
    @required this.unfilledStar,
  })  : assert(value != null),
        super(key: key);

  @override
  Widget build(BuildContext context) {
    return Row(
      mainAxisSize: MainAxisSize.min,
      children: List.generate(5, (index) {
        return index < value ? filledStar : unfilledStar;
      }),
    );
  }
}

class StarDisplay extends StarDisplayWidget {
  const StarDisplay({Key key, int value = 0})
      : super(
          key: key,
          value: value,
          filledStar: const Icon(Icons.star),
          unfilledStar: const Icon(Icons.star_border),
        );
}

class StarRating extends StatelessWidget {
  final void Function(int index) onChanged;
  final int value;
  final IconData filledStar;
  final IconData unfilledStar;

  const StarRating({
    Key key,
    @required this.onChanged,
    this.value = 0,
    this.filledStar,
    this.unfilledStar,
  })  : assert(value != null),
        super(key: key);

  @override
  Widget build(BuildContext context) {
    final color = Theme.of(context).accentColor;
    final size = 36.0;
    return Row(
      mainAxisSize: MainAxisSize.min,
      children: List.generate(5, (index) {
        return IconButton(
          onPressed: onChanged != null
              ? () {
                  onChanged(value == index + 1 ? index : index + 1);
                }
              : null,
          color: index < value ? color : null,
          iconSize: size,
          icon: Icon(
            index < value ? filledStar ?? Icons.star : unfilledStar ?? Icons.star_border,
          ),
          padding: EdgeInsets.zero,
          tooltip: "${index + 1} of 5",
        );
      }),
    );
  }
}

import 'package:flutter/material.dart';

class StarDisplayWidget extends StatelessWidget {
  final int value;
  final Widget filledStar;
  final Widget unfilledStar;
  final double size;
  final Color color;
  final int marginFactor;

  const StarDisplayWidget({
    Key key,
    this.value = 0,
    this.filledStar,
    this.unfilledStar,
    this.color = Colors.orange,
    this.size = 20,
    this.marginFactor = 5,
  })  : assert(value != null),
        super(key: key);

  @override
  Widget build(BuildContext context) {
    return Row(
      mainAxisSize: MainAxisSize.min,
      mainAxisAlignment: MainAxisAlignment.start,
      crossAxisAlignment: CrossAxisAlignment.end,
      children: List.generate(5, (index) {
        return Container(
          width: size - size / marginFactor,
          height: size,
          child: Icon(
            index < value
                ? filledStar ?? Icons.star
                : unfilledStar ?? Icons.star_border,
            color: color,
            size: size,
          ),
        );
      }),
    );
  }
}

class StarRating extends StatelessWidget {
  final void Function(int index) onChanged;
  final int value;
  final IconData filledStar;
  final IconData unfilledStar;
  final double size;
  final Color color;
  final int marginFactor;

  const StarRating({
    Key key,
    @required this.onChanged,
    this.value = 0,
    this.filledStar,
    this.unfilledStar,
    this.color = Colors.orange,
    this.size = 20,
    this.marginFactor = 5,
  })  : assert(value != null),
        super(key: key);

  @override
  Widget build(BuildContext context) {
    return Row(
      mainAxisAlignment: MainAxisAlignment.start,
      mainAxisSize: MainAxisSize.min,
      children: List.generate(5, (index) {
        return RawMaterialButton(
          child: Icon(
            index < value
                ? filledStar ?? Icons.star
                : unfilledStar ?? Icons.star_border,
            color: color,
            size: size,
          ),
          materialTapTargetSize: MaterialTapTargetSize.shrinkWrap,
          shape: CircleBorder(),
          constraints: BoxConstraints.expand(
              width: size - size / marginFactor, height: size),
          padding: EdgeInsets.zero,
          highlightColor: Colors.transparent,
          splashColor: Colors.transparent,
          onPressed: onChanged != null
              ? () {
                  onChanged(value == index + 1 ? index : index + 1);
                }
              : null,
        );
      }),
    );
  }
}

Great work Mortadda, I used it and it works perfectly.
However, I used the first version because the 2nd one with modifications generates a RenderFlex Overflow.

Thank you